The present invention generally relates to system for the intravenous infusion of medication in accordance with a predetermined medical therapy. Medication delivery systems are provided which are useful for improving the ease of administration therapy.
Intravenous medications including antibiotics and the like may be administered intermittently over a period of time. Each administration of an intravenous therapy generally follows a predefined procedure that often includes a series of manual steps including saline flushes and generally terminates with the application of anti-clotting medication. The manual steps in the therapy procedures are a principle source of error, infection, and other complications that may arise during intermittent infusion therapy.
Accordingly, there is still a need in the art for systems which improve the administration of intermittent medication infusion therapy. The present invention satisfies this and other needs in the art.
The present invention overcomes many of the problems in the art by providing a medication delivery system for administering an infusion therapy using a mechanical medication delivery pump and related fluid container. Medications in a flexible multi-chambered bag of the container are expelled from the bag by the pump into an administration set and delivered to an infusion site. The administration set may further comprise a restrictor which limits the rate at which fluid is administered to the patient. The system provides improved infusion therapy administration which is particularly advantageous for reducing errors, infections and other complications associated with manual infusion techniques.
In one embodiment of the invention, the medication delivery system includes a bag having at least one chamber containing a medication fluid; a pump having a constant force spring for compressing the bag to generate a predetermined pressure in the chamber based on the chamber""s configuration, and an administration set. The administration set receives the medication fluid from the bag at the predetermined pressure and delivers the medication fluid to an infusion site at a predetermined flow rate. The administration set may include a micro-bore tubing having a length and an inner diameter that establishes the predetermined flow rate. The administration set also may include an air-eliminating filter for eliminating air bubbles from the medication fluid before delivery of the fluid to the infusion site.
The medication delivery system may further include a manifold between the bag and the administration set. The manifold may include at least one check valve associated with a respective chamber of the bag. By introducing fluid into the administration set under sufficient pressure and maintaining it there (e.g., by use of a clamp on the tubing of the administration set), a hydraulic lock may be formed that holds the check valve(s) closed and prevents unintentional flow from the bag during handling. The hydraulic lock may be overcome upon the application of a threshold pressure on the chamber (i.e., at least the cracking pressure of the check valve).
Another embodiment of the invention resides in a method for filling a fluid delivery bag having a plurality of chambers. A first predetermined fluid volume is measured and at least one chamber is constrained to a second predetermined volume. The plurality of chambers are filled through a shared bulk fill port with the first predetermined volume of fluid such that a constrained chamber is filled with the second predetermined volume of fluid and remaining chamber(s) is/are filled with a predetermined volume of fluid determined by the first predetermined volume of fluid minus the fluid of the constrained chamber (and the volume of any intervening chambers).